JP5951964B2 - Optical path changing member and optical module - Google Patents

Description

  The present invention relates to an optical path conversion member that changes an optical path by bending an optical fiber for optical path conversion, and an optical module that includes the optical path conversion member.

  In optically connecting an optical element surface-mounted on a substrate and an optical fiber extending in a direction parallel to the mounting surface on which the optical element is mounted, the following Patent Document 1 discloses an optical path such as a 45 degree mirror or a prism. A method of connecting a conversion component and a lens in combination and a method of bending and connecting an optical fiber are disclosed.

  In the above-described method of connecting the optical path conversion component and the lens in combination, a relatively large space is required between the lens and the optical element. For this reason, the portion related to the optical connection, that is, the height dimension of the optical module is large. As a result, there is a problem that it is difficult to reduce the size of the optical module.

  Moreover, in the method of bending and connecting the above optical fiber, there are a method of bending by heating and melting and a method of bending using a holding member when bending the optical fiber. The method of bending an optical fiber by heating and melting is not particularly disclosed in Patent Document 1 below, but has a problem that the optical fiber is difficult to handle and the productivity is poor. On the other hand, regarding the method of bending with the holding member, two examples are disclosed in Patent Document 1 below. The first is an example disclosed in the background art section of Patent Document 1 below, and in this case, it is difficult to change the optical path on the substrate. The second is an example according to the invention of Patent Document 1 below. Hereinafter, a second example will be described with reference to the drawings.

  In FIG. 12, reference numeral 101 indicates an optical module. The optical module 101 includes a surface emitting or surface receiving optical element 103 mounted on the upper surface of the substrate 102, a plurality of optical fibers 104 extending in a direction parallel to the upper surface of the substrate 102, and the plurality of optical fibers 104. An optical path conversion member 105 that converts the optical path and optically connects to the optical element 103 and a fixing portion 106 that places and fixes the optical path conversion member 105 on the upper surface of the substrate 102 are configured.

  The optical path conversion member 105 includes a first holding member 107 and a second holding member 108 assembled to the first holding member 107. The optical path changing member 105 has a structure in which when the second holding member 108 is assembled to the first holding member 107, the optical path changing portions 109 of the plurality of optical fibers 104 bend to the optical element 103 side in accordance with the assembly. Is formed. Reference numeral 110 indicates a bent portion of the optical path changing portion 109.

  The first holding member 107 is a member that serves as a base in the optical path conversion member 105, and is formed across the flat upper surface 111, the curved distal end surface 112 smoothly extending from the upper surface 111, and the upper surface 111 and the curved distal end surface 112. And a plurality of positioning grooves 113. The plurality of positioning grooves 113 are formed so as to accommodate the lower edge side of the optical path changing portion 109 in the plurality of optical fibers 104. The plurality of positioning grooves 113 are formed so that the optical path changing portions 109 of the plurality of optical fibers 104 can be aligned.

  The second holding member 108 is a lid-like member in the optical path conversion member 105, and has a flat lower surface 114 that faces the upper surface 111 of the first holding member 107, and the first holding member 107 that continues smoothly from the lower surface 114. And a curved surface 115 opposite to the curved distal end surface 112. The lower surface 114 and the curved surface 115 are formed as surfaces for pressing the upper edge side of the optical path changing portions 109 of the plurality of optical fibers 104 accommodated in the plurality of positioning grooves 113.

JP 2008-52028 A

  In the conventional optical path changing member 105, the optical path changing portions 109 of the plurality of optical fibers 104 are pressed by the second holding member 108. Specifically, the straight portion 116 of the optical path conversion portion 109 is pressed by the lower surface 114 of the second holding member 108, and the bent portion 110 of the optical path conversion portion 109 is pressed by the curved surface 115. Therefore, the fact that the straight portion 116 and the bent portion 110 are pressed as described above is in a state where there is no air layer on the upper edge side (outer edge side), and therefore the refractive index difference is smaller than when there is an air layer. As a result, there is a problem that bending loss increases. If the bending radius becomes very small due to pressing, there is a risk that bending loss will increase.

  Further, in the above-described conventional optical path conversion member 105, the upper surface 111 and the curved tip surface 112 are formed on the first holding member 107. However, when viewed between the curved tip surface 112 and the optical element 103, the surface perpendicular to the upper surface of the substrate 102 is formed in a shape that does not exist. Therefore, there is a possibility that the distal end portion of the optical path changing portion 109 of the optical fiber 104 may be disposed obliquely with respect to the optical element 103, and there is a problem that connection loss with the optical element 103 increases. .

  Further, in the optical path conversion member 105 of the conventional technique, a plurality of positioning grooves 113 are formed over the upper surface 111 and the curved distal end surface 112 of the first holding member 107. Therefore, it is difficult to mold a mold for forming the positioning groove 113 on the curved front end surface 112. If the groove position or the groove depth varies, the front end position of the optical path changing portion 109 is shifted, and as a result, the distance from the optical element 103 is reduced. There is a problem that lossy connection becomes difficult.

  Furthermore, in the optical path conversion member 105 of the above prior art, if the length management of the optical path conversion portion 109 of the optical fiber 104 is not strictly performed, the tip position of the optical path conversion portion 109 may be too close to the optical element 103. There is a risk of being too far away. However, when length management is strictly performed, there is a problem that productivity is deteriorated. If the length management is not strictly performed, it is necessary to polish the tip of the optical path conversion portion 109. Polishing the tip requires a plurality of steps and takes time.

  The present invention has been made in view of the above circumstances, and it is an object to provide an optical path conversion member and an optical module that enable optical connection with low loss and that can improve productivity. To do.

The optical path conversion member according to claim 1, which has been made to solve the above problems, includes an optical fiber for optical path conversion, a first holding member and a second holding member assembled so as to sandwich the optical fiber for optical path conversion. An optical path converting member that is bent when the first holding member and the second holding member are assembled together by arranging the optical path converting optical fiber at a predetermined position. The optical path converting optical fiber has a bent part formed by bending the optical path converting optical fiber accompanying the assembly, and is directed to the incident end and the outgoing end, respectively, one end and the other end of the bent part. The first holding member includes an incident side plane part and an output side plane part, and the incident side plane part and the output side. An arc portion that connects the plane portion and acts on the bending of the optical fiber for path conversion accompanying the assembling, and the arc portion is disposed on the inner edge side of the bending portion, and the second holding members are mutually connected. An incident side plane portion and an emission side plane portion that are arranged to be orthogonal to each other, and a space portion that is disposed near the intersection of the incident side plane portion and the emission side plane portion and on the outer edge side of the bent portion. The space portion is formed in a shape in which the space expands in a direction away from the outer edge of the bent portion, and is in a position corresponding to the incident side plane portion of the first holding member in the incident side plane portion of the second holding member. In addition, an incident side groove portion for accommodating the incident side linear portion is provided, and the emission side linear portion is accommodated at a position corresponding to the emission side plane portion of the first holding member in the emission side plane portion of the second holding member. the exit side groove which is provided, the incident-side The portion extends from an edge portion of the incident side plane portion to an intermediate portion of the incident side plane portion, and an edge of the end portion on the space portion side of the incident side groove portion and a part of the optical fiber for path change. The exit-side groove portion extends from an edge of the exit-side flat portion to an intermediate portion of the exit-side flat portion, and an edge of the exit portion on the space portion side of the exit-side groove and the optical path conversion A part of the optical fiber for contact, and an edge of the incident side groove portion on the space portion side and an edge of the emission side groove portion on the space portion side end of the bending portion are the space. The bent portion is disposed and formed at a position where the bent portion can come into contact with the second portion when the second portion moves to the portion side .

According to the present invention having such a feature, the optical path converting optical fiber has a space portion that is disposed on the outer edge side of the bent portion of the optical path converting optical fiber and has a shape in which the space expands in a direction away from the outer edge. It can provide as an optical path changing member in which an air layer exists in an outer edge of a bent part. According to the present invention, the refractive index difference between the optical path changing optical fiber and the air layer can be increased as compared with the case without the air layer, and thus the bending loss can be reduced. For this reason, the bend radius of the optical fiber for optical path conversion can be reduced, so that it can be miniaturized when used in an optical module.
In addition, according to the present invention, the optical path converting optical fiber has an incident side plane part and an output side plane part sandwiching the incident side linear part and the output side linear part, and the incident side plane part and the output side plane part are circular arcs. Since it is arranged and formed so as to be continuous with the part, the front end position and the rear end position of the optical fiber for optical path conversion can be stabilized.
Furthermore, according to the present invention, since the incident side plane part and the emission side plane part are arranged and formed in the orthogonal direction, for example, an optical element (surface emitting or surface receiving optical element) surface-mounted on a substrate And an optical fiber extending in a direction parallel to the mounting surface on which the optical element is mounted can be optically connected. According to the present invention, the optical axis of the optical element and the optical axis of the optical fiber for path change can be arranged in parallel (coaxially arranged). In addition, the optical axis of the optical fiber parallel to the substrate and the optical axis of the optical fiber for optical path conversion can be arranged in parallel (coaxially arranged).

The optical path conversion member of the present invention according to claim 2 relates to the optical path conversion member according to claim 1 , wherein the optical fiber for optical path conversion is assembled with the first holding member and the second holding member, The bending portion is formed by bending the bending portion in a direction away from the arc portion, and the space portion is formed in a shape in which the space exists on an outer edge side of the bending deflection portion. And

  According to the present invention having such characteristics, the optical path converting optical fiber is disposed on the outer edge side of the bent portion, and has a space portion having a shape in which the space extends in a direction away from the outer edge. Since the bending portion is formed by bending in a direction away from the bending portion and a space exists on the outer edge side of the bending bending portion, either the bending portion or the bending bending portion of the optical fiber for optical path conversion is used. Even if it exists, it can provide as an optical path conversion member in which an air layer exists in this outer edge.

  In addition, according to the present invention, when the bending path is formed in the optical path conversion optical fiber, the tip of the optical path conversion optical fiber is pushed into the optical path conversion member, and at this time, the predetermined position is reached. If the optical path conversion member is used for an optical module, the positional relationship with the optical element can be improved. That is, the tip of the optical path conversion optical fiber can be disposed at an optimum position with respect to the optical element without strictly managing the length of the optical path conversion optical fiber.

  If the tip of the optical fiber for optical path conversion is pushed into the optical path conversion member as described above, polishing for adjusting the tip position can be made unnecessary. The polishing of this portion requires a plurality of steps and takes time, so that an increase in manufacturing cost can be suppressed.

An optical module of the present invention according to claim 3 , which has been made to solve the above problems, includes an optical element surface-mounted on a substrate, an optical fiber extending in a direction intersecting the optical axis of the optical element, The optical path conversion member according to claim 1 or 2 disposed between the optical element and the optical fiber.

According to the present invention having such characteristics, an optical module including the optical path changing member according to claim 1 or 2 is obtained.

According to the first aspect of the present invention, since the space portion is formed, an optical path conversion member having an air layer on the outer edge side of the bent portion of the optical path conversion optical fiber is provided. There exists an effect that the loss in a bending part can be reduced. Therefore, according to the present invention, it is possible to provide an optical path conversion member that can be optically connected with low loss. In addition, according to the present invention, it is possible to reduce the bending radius of the optical fiber for path conversion, and thus, when used in an optical module, there is an effect that this miniaturization can be achieved.

Further, according to the present invention described in claim 1, since the incident side groove portion and the emission side groove portion are formed only on the incident side plane portion and the emission side plane portion, the workability of the mold is improved and the groove portion is improved. Variations in position and depth are less likely to occur, and the front end position and rear end position of the optical path conversion optical fiber can be stabilized. Therefore, there is an effect that a low-loss connection with an optical element or an optical fiber can be achieved. According to the present invention, there is an effect that it is possible to provide an optical path conversion member capable of optical connection with low loss.

Furthermore, according to this invention described in Claim 1, in addition to said effect, there exist the following effects. That is, in optically connecting an optical element surface-mounted on a substrate and an optical fiber extending in a direction parallel to the mounting surface on which the optical element is mounted, the optical axis of the optical fiber for path change is used for the optical element and the optical fiber. There is an effect that it can be arranged in parallel to each optical axis of the fiber. Therefore, according to this invention, there exists an effect that a better optical path conversion member can be provided. In addition, there is an effect that it is possible to provide an optical path conversion member with good productivity.

According to the second aspect of the present invention, by forming the space portion, an optical path conversion member in which an air layer exists on the outer edge side of the bent portion of the optical fiber for optical path conversion and also on the outer edge side of the bent bending portion is obtained. As a result, there is an effect that the loss at the bent portion and the bent portion of the optical fiber for optical path conversion can be reduced. Therefore, according to the present invention, it is possible to provide an optical path conversion member that can be optically connected with low loss. Further, according to the present invention, when forming the bending deflection portion from the bending portion, for example, if the tip of the optical path conversion optical fiber is pushed into the optical path conversion member, the tip of the optical path conversion optical fiber is optimized. There exists an effect that it can arrange in a position. Therefore, according to the present invention, it is possible to simplify the length management of the optical fiber for optical path conversion, and it is possible to improve the productivity of the optical path conversion member. Furthermore, according to the present invention, in adjusting the tip position of the optical fiber for optical path conversion, it is pushed into the optical path conversion member as described above, thereby eliminating an effect of eliminating a polishing process that requires a plurality of steps. Play. Therefore, according to the present invention, it is possible to suppress an increase in manufacturing cost.

According to the third aspect of the present invention, since the optical path conversion member according to the first or second aspect is included in the configuration, an optical connection with low loss is possible, and productivity is improved. There is an effect that it is possible to provide an optical module that can be used.

It is sectional drawing of the optical path changing member and optical module which concern on this invention. It is a perspective view of an optical path changing member. It is a perspective view of a 1st holding member. It is sectional drawing of a 1st holding member. It is a perspective view of a 2nd holding member. It is sectional drawing of the state which assembled | attached the 1st holding member and the 2nd holding member. It is a figure which concerns on manufacture of an optical path conversion member, and is explanatory drawing of a 1st process. It is a figure which concerns on manufacture of an optical path conversion member, and is explanatory drawing of a 2nd process. It is a figure which concerns on manufacture of an optical path conversion member, and is explanatory drawing of a 3rd process. It is a figure which concerns on manufacture of an optical path conversion member, and is explanatory drawing of a 4th process. It is explanatory drawing of the bending part and bending bending part of the optical fiber for optical path conversion. It is a figure of the optical path conversion member and optical module of a prior art example, (a) is sectional drawing of the optical module of a prior art example, (b) is a disassembled perspective view of the optical path conversion member of a prior art example.

  The optical path changing member includes an optical path changing optical fiber, a first holding member, and a second holding member. When the optical path conversion optical fiber is bent to form a bent portion in association with the assembly of the first holding member and the second holding member, the arc portion of the first holding member is formed on the inner edge side of the bent portion. Is disposed, and the space portion of the second holding member is disposed on the outer edge side of the bent portion. In the optical fiber for optical path conversion, after assembling the first holding member and the second holding member, the bending portion is bent in the direction away from the arc portion in order to adjust the tip position of the optical fiber to form the bending deflection portion. . Even if the bending deflection portion is formed, a space portion exists on the outer edge side.

  The optical module includes an optical element that is surface-mounted on a substrate, an optical fiber that extends in a direction parallel to the mounting surface on which the optical element is mounted, and the optical path conversion member that optically connects them. . The optical module has a configuration and structure effective when optical path conversion is required.

  Hereinafter, embodiments will be described with reference to the drawings. FIG. 1 is a cross-sectional view of an optical path conversion member and an optical module according to the present invention. 2 is a perspective view of the optical path conversion member, FIGS. 3 and 4 are perspective views and sectional views of the first holding member, FIG. 5 is a perspective view of the second holding member, and FIG. 6 is a first holding member and a second holding member. FIG. 7 to FIG. 10 are explanatory views relating to the manufacture of the optical path changing member, and FIG. 11 is an explanatory view of the bent portion and the bent portion of the optical path changing optical fiber.

  In the following description, specific shapes, materials, numerical values, directions, and the like are examples for facilitating the understanding of the present invention, and can be appropriately changed according to use, purpose, specifications, and the like. To do.

  In FIG. 1, reference numeral 1 indicates an optical module. The optical module 1 includes a surface-emitting or surface-receiving optical element 3 mounted on the upper surface of a substrate 2, an optical fiber 4 extending in a direction crossing the optical axis of the optical element 3, and the optical element 3 and the optical fiber 4. The optical path conversion member 5 is disposed between the optical path conversion member 5 and the fixing portion 6 for mounting and fixing the optical path conversion member 5 on the upper surface of the substrate 2. First, each component described above will be described.

  In this embodiment, the optical fiber 4 is arranged so as to extend in a direction parallel to the upper surface (mounting surface) of the substrate 2 on which the optical element 3 is mounted (assumed as an example). That is, the optical fiber 4 is disposed in a direction orthogonal to the optical axis in the present embodiment.

  Known optical fibers 4 and optical elements 3 are used.

  The optical path changing member 5 includes an optical path changing optical fiber 7 and a first holding member 8 and a second holding member 9 assembled so as to sandwich the optical path changing optical fiber 7.

  In this embodiment, two (two) optical elements 3, optical fibers 4, and optical path changing optical fibers 7 are provided (the number is an example). Regarding the optical element 3, one is for transmission and the other is for reception. In other words, the light-emitting optical element 3a for transmission is shown by a thin lead line, and the light-receiving optical element 3b for reception is shown by a thin lead-out line. Similarly, the optical fiber 4 and the optical path conversion optical fiber 7 are for transmission and reception depending on the optical element 3. That is, the optical fiber 4a for transmission and the optical path conversion optical fiber 7a are illustrated with a thin lead line, and the optical fiber 4b for reception and optical path conversion are illustrated with a thin dashed line. An optical fiber 7b is formed. Note that the same optical fiber 4 and optical path converting optical fiber 7 are used for both transmission and reception in this embodiment.

  A bending-resistant optical fiber is used as the optical path converting optical fiber 7. This bending-resistant optical fiber is an optical fiber having a large refractive index difference between the core and the cladding in order to reduce bending loss. For example, a multimode optical fiber having a trench type refractive index distribution is used. The optical fiber 7 for optical path conversion is manufactured by raising the screening level so that it does not break even when it is bent with a small diameter, or a fiber having an outer diameter smaller than that of a general-purpose product is used. . The optical path converting optical fiber 7 is used in a state where this coating is peeled off in this embodiment.

  The optical path converting optical fiber 7 has a length that is longer than the length of the sandwiched portion. It may be longer than the length of the portion to be sandwiched, which means that it is not necessary to strictly manage the length of the optical fiber for optical path conversion at the time before being sandwiched between the first holding member 8 and the second holding member 9. That is good.

  The optical fiber 7 for optical path conversion is bent with the assembly of the first holding member 8 and the second holding member 9 to form a bent portion 10 (see FIG. 8), and one end and the other end of the bent portion 10 The straight portions 11 and 12 are also formed so as to be continuous with each other.

  The linear portion 11 is disposed on the optical element 3 side. In the case of the optical element 3a, this portion is added to the incident-side linear portion 11a described in the claims, and in the case of the optical element 3b, This portion corresponds to the output-side straight portion 11b described in the claims. On the other hand, the linear portion 12 is disposed on the optical fiber 4 side. In the case of the optical element 3a, this portion is added to the outgoing side linear portion 12a described in the claims, and in the case of the optical element 3b. This portion corresponds to the incident-side straight portion 12b described in the claims.

  After assembling the first holding member 8 and the second holding member 9, the optical path converting optical fiber 7 bends the bent portion 10 (see FIG. 8) in a predetermined direction (described later with reference to FIG. 8). As a result, the bending deflection portion 13 is formed.

  In the optical fiber 7 for optical path conversion, when the end face on the optical element 3 side is a front end face 14 and the end face on the optical fiber 4 side is a rear end face 15, the front end face 14 will be described later of the first holding member 8 and the second holding member 9. The lower surfaces 17 and 25 are arranged so as to be flush with each other (the arrangement will be described later). The rear end surface 15 is also processed so as to be flush with rear surfaces 19 and 27 (to be described later) of the first holding member 8 and the second holding member 9 (the processing will be described later). Here, the left-right direction in FIG. 1 is defined as front and rear, the vertical direction in FIG. 1 is defined as left and right, and the up-down direction in FIG.

  1 to 4, the first holding member 8 is a block-shaped resin molded product (male mold) molded by filling a molding die with a resin material, and includes a flat upper surface 16 and the upper surface 16. , A flat front surface 18 that is perpendicular to the upper surface 16 and the lower surface 17, a rear surface 19 that is also perpendicular to the upper surface 16 and the lower surface 17, and a left side surface 20 that is perpendicular to each of the surfaces. It has a right side surface 21, a curved arc portion 22 that smoothly connects the upper surface 16 and the front surface 18, and a guide protrusion 23 that protrudes from the upper surface 16.

  If the linear part 12 arrange | positioned here on the upper surface 16 is the radiation | emission side linear part 12a, this part shall correspond to the radiation | emission side plane part 16a described in the claim. Moreover, if the linear part 12 is the incident side linear part 12b, this part shall correspond to the incident side plane part 16b described in the claim. On the other hand, if the straight part 11 arrange | positioned here is the incident side linear part 11a, this part shall correspond to the incident side plane part 18a described in the claim. Further, if the straight portion 11 is the emission side straight portion 11b, this portion corresponds to the emission side flat portion 18b described in the claims.

  The front surface 18 and the upper surface 16 are formed so that the straight portions 11 and 12 of the optical path conversion optical fiber 7 can be arranged in parallel to the optical axes of the optical element 3 and the optical fiber 4.

  The arc portion 22 is formed in a curved surface shape as described above. In the case of FIG.1 and FIG.4, the circular arc part 22 is formed in the curved-surface shape (arc shape) which becomes convex in the paper surface diagonally upper left direction. Such an arc portion 22 is formed so that it can be bent by pressing the optical fiber 7 for optical path conversion so as not to break. The arc portion 22 is formed as a portion that acts on the bending of the optical path converting optical fiber 7.

  The guide protrusion 23 is a guide portion when assembled with the second holding member 9 and is formed in a rectangular parallelepiped shape extending straight forward from the position of the rear surface 19. The guide protrusion 23 is disposed and formed on the upper surface 16 between the emission side plane portion 16a and the incident side plane portion 16b.

  In FIG. 1, FIG. 2, FIG. 5 and FIG. 6, the second holding member 9 is a block-shaped resin molded product (female mold) that is molded by filling a molding die with a resin material and is flat. A top surface 24, a bottom surface 25 parallel to the top surface 24 and flat, a front surface 26 perpendicular to the top surface 24 and the bottom surface 25, a rear surface 27 which is also perpendicular to the top surface 24 and the bottom surface 25, and is perpendicular to the above surfaces. The flat left side surface 28 and the right side surface 29, the concave portion 30 formed so as to open the lower surface 25 and the rear surface 27, and the guide groove formed by cutting out the rear surface 27 so as to communicate with the upper surface 24 and the concave portion 30. 31.

  The concave portion 30 is an assembly portion with respect to the first holding member 8, and is a flat concave upper surface 32 that is parallel to the upper surface 24, a flat concave front surface 33 that is perpendicular to the concave upper surface 32, and a vertical flat surface that is also perpendicular to the concave upper surface 32. A recess left side surface 34 and a recess right side surface 35 are provided. A guide groove 31 is formed at the center position of the concave upper surface 32. The guide groove 31 is a portion that guides the guide protrusion 23 of the first holding member 8, and is notched so as to extend straight up to the position of the concave front surface 33.

  If the linear part 12 arrange | positioned here is the radiation | emission side linear part 12a, it shall correspond to the radiation | emission side plane part 32a described in the claim. Moreover, if the linear part 12 is the incident side linear part 12b, it shall correspond to the incident side plane part 32b described in the claim. On the other hand, if the linear part 11 arrange | positioned here is the incident side linear part 11a, it shall correspond to the incident side plane part 33a described in the claim. Moreover, if the straight part 11 is the radiation | emission side linear part 11b, it shall correspond to the radiation | emission side plane part 33b described in the claim.

  The concave front surface 33 and the concave upper surface 32 are formed so that the straight portions 11 and 12 of the optical path converting optical fiber 7 can be arranged in parallel to the optical axes of the optical element 3 and the optical fiber 4.

  A space portion 36 is formed in the vicinity of the intersection between the concave front surface 33 and the concave upper surface 32.

  The space portion 36 is a space generated by assembling the first holding member 8 and has a shape in which the space expands in a direction away from the arc portion 22 of the first holding member 8, and the optical path converting optical fiber 7 is bent. It is formed in such a shape that the space expands in a direction away from the outer edge of the portion 10 (see FIG. 8) and the outer edge of the bending deflection portion 13.

  As will be described later, the space portion 36 has a function of providing a bending space for the optical path conversion optical fiber 7 and a light confinement effect by the air layer and the side surface of the optical path conversion optical fiber 7 to reduce bending loss. It has two functions.

  Further, as will be understood later, the space portion 36 provides a bending space for the optical path converting optical fiber 7, and therefore the lower surfaces 17 and 25 of the first holding member 8 and the second holding member 9. An optical fiber tip portion (tip portion 40 to be described later) protruding slightly from the optical fiber can be pushed in.

  Groove portions 37 and 38 are formed in the concave front surface 33 and the concave upper surface 32. The groove portions 37 and 38 are formed as groove-shaped portions that receive and position the optical path converting optical fiber 7. The groove portions 37 and 38 are disposed and formed at positions corresponding to the front surface 18 and the upper surface 16 of the first holding member 8. The groove portions 37 and 38 are formed so as to extend straight. The groove portions 37 and 38 are formed to extend slightly toward the space portion 36 side. The groove portions 37 and 38 are formed in a V-shaped groove in this embodiment (not limited to this, for example, a U-shaped groove or a rectangular groove may be used).

  If the linear part 11 accommodated here is the incident side linear part 11a, this part shall correspond to the incident side groove part 37a described in the claim. Moreover, if the straight part 11 is the output side straight part 11b, this part shall correspond to the output side groove part 37b described in the claims. On the other hand, if the linear part 12 accommodated here is the radiation | emission side linear part 12a, this part shall correspond to the radiation | emission side groove part 38a described in the claim. Further, if the straight line portion 12 is the incident side straight line portion 12b, this portion corresponds to the incident side groove portion 38b described in the claims.

  In the present embodiment, the groove portions 37 and 38 are formed on the second holding member 9 side, but it is not limited thereto. That is, it may be formed on the first holding member 8 side or on both the first holding member 8 and the second holding member 9. However, in order to simplify the processing of the molding die and to improve the processing of the molding die, the arc portion 22 is not formed (this embodiment in which the groove portions 37 and 38 are formed on a flat surface). The example can facilitate the processing of the mold and improve the dimensional accuracy, thus contributing to optical connection with low loss).

  Next, the assembly of the optical path conversion member 5 and the optical module 1 will be described based on the above configuration and structure. The assembly of the optical path conversion member 5 is completed through the following first to fourth steps.

  In FIG. 7, in the first step, the coating of the optical path conversion optical fiber 7 (using a bending-resistant optical fiber) is peeled off, and the end surface 39 of the optical path conversion optical fiber 7 is made smooth by cleaving (cutting). . Then, after that, in the state shown in FIG. 7, that is, at the positions of the lower surface 25 and the rear surface 27 of the second holding member 9, an operation of arranging the optical path conversion optical fiber 7 so as to enter the groove portions 37 and 38 is performed. It is to be noted that the length management of the optical path converting optical fiber 7 is not strictly performed (however, it is assumed that the length is longer than the length sandwiched between the first holding member 8 and the second holding member 9). In addition, the amount of protrusion described later shall be taken into consideration).

  In the first step, the optical path converting optical fiber 7 is disposed in a state of protruding from the lower surface 25 and the rear surface 27 of the second holding member 9.

  7 and 8, in the second step, an operation of assembling the first holding member 8 and the second holding member 9 is performed. Specifically, the first holding member 8 is slid with respect to the second holding member 9 to assemble them. At this time, the optical path converting optical fiber 7 is bent by pressing from the arc portion 22 of the first holding member 8 to form the bent portion 10. Moreover, the linear parts 11 and 12 are also formed in the state which follows the one end and the other end of the bending part 10, respectively. The bent portion 10 is formed by being bent with the curvature of the arc portion 22. The straight portion 11 is sandwiched between the concave front surface 33 and the front surface 18, and the linear portion 12 is sandwiched between the concave upper surface 32 and the upper surface 16.

  In the second step, the tip portion 40 of the optical path converting optical fiber 7 is adjusted to protrude from the lower surfaces 17 and 25 at 0.42 mm or less (the protrusion amount will be described later with reference to FIG. 11). ).

  8 and 9, in the third step, the distal end portion 40 of the optical path conversion optical fiber 7 protruding from the lower surfaces 17 and 25 is pressed by a flat plate 41 such as a glass plate, and the distal end of the optical path conversion optical fiber 7 is pressed. The operation of making the surface 14 flush with the lower surfaces 17 and 25 is performed. When the distal end portion 40 of the optical path converting optical fiber 7 is pushed, the bent portion 10 bends away from the arc portion 22 in the space 36 formed by assembling the first holding member 8 and the second holding member 9. As a result, the bending deflection portion 13 is formed.

  9 and 10, in the fourth step, the first holding member 8 is formed with an adhesive in a state where the distal end portion 40 of the optical fiber 7 for optical path conversion is pressed by the flat plate 41 and the bending bending portion 13 is formed. Then, the second holding member 9 and the optical path converting optical fiber 7 are bonded and fixed. The hole for injecting the adhesive is formed at an appropriate position of the first holding member 8 or the second holding member 9. It is assumed that the adhesive is not injected into the space 36, but if it is injected, an adhesive having a refractive index smaller than that of the optical fiber 7 for optical path conversion is used in order to reduce bending loss. Shall.

  After the adhesive fixing, the rear end portion 42 of the optical path converting optical fiber 7 protruding from the rear surfaces 19 and 27 is cut and polished at the positions of the rear surfaces 19 and 27. Thereby, the rear end face 15 of the optical path converting optical fiber 7 which is flush with the rear faces 19 and 27 is formed, and a series of assembly of the optical path changing member 5 is completed.

  Here, the protrusion amount (0.42 mm or less) will be described with reference to FIG.

  In FIG. 11, the bending portion 10 of the optical path converting optical fiber 7 is in a state before being pushed in, and the bending radius at this time is R. Moreover, the bending bending part 13 of the optical fiber 7 for optical path conversion is in the state after pushing, and let the bending radius at this time be r.

  When the length in the space portion 36 before the optical path converting optical fiber 7 is pushed is L, the length L is expressed by Expression (1). That is, L = πR / 2 (1).

  When the length in the space portion 36 of the optical path converting optical fiber 7 in the pushed-in state is M, this length M is expressed by Expression (2). That is, M = (πr / 2) +2 (R−r) (2).

  When the pushing amount is x, Expression (3) is established. That is, L + x = M (3).

  When the variation of the bending radius is set to 1 mm, x = 0.429 mm from the equation (3) when R−r = 1 mm. Therefore, if the pushing amount x is 0.42 mm or less, that is, the protrusion amount is 0.42 mm or less, the fluctuation of the bending radius can be suppressed to 1 mm or less.

  Returning to FIG. 1, when the optical path changing member 5 is disposed between the optical element 3 surface-mounted on the substrate 2 and the optical fiber 4, the assembly of the optical module 1 is completed.

  As described above with reference to FIGS. 1 to 11, according to the optical path conversion member 5 and the optical module 1, the outer edge of the bending portion 10 of the optical path conversion optical fiber 7 and the bending deflection portion 13 are formed by the space portion 36. Since an air layer is present at the outer edge of the film, bending loss can be reduced and the bending radius can be reduced. Therefore, the height of the optical path conversion member 5 can be reduced, and the optical module 1 (optical connector) can be downsized.

  Further, according to the optical path conversion member 5 and the optical module 1, it is not necessary to polish the tip surface 14 of the optical path conversion optical fiber 7 on the optical element 3 side. As a result, the manufacturing cost is reduced and the productivity is improved. Can be made.

  Furthermore, according to the optical path conversion member 5 and the optical module 1, the optical axis of the linear portion 11 of the optical path conversion optical fiber 7 is arranged in parallel to the optical axis of the optical element 3 by the front surface 18 and the concave front surface 33 (coaxially). As a result, the connection loss with the optical element 3 can be reduced. Similarly, the optical axis of the linear portion 12 of the optical fiber 7 for optical path conversion is also arranged in parallel (coaxially) with the optical axis of the optical fiber 4, and as a result, the connection loss with the optical fiber 4 is reduced. Can do.

  Furthermore, according to the optical path changing member 5 and the optical module 1, since the groove portions 37 and 38 are not formed in the arc portion 22 of the second holding member 9, the groove portions 37 and 38 are provided on the curved surface. Since the structure is not, processing of the molding die can be facilitated. Since straight groove processing is easy and dimensional accuracy can be easily obtained, variations in groove position and groove depth can be minimized. Therefore, these can be connected between the optical element 3 and the optical fiber 4 with low loss.

  It goes without saying that the present invention can be variously modified without departing from the spirit of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Optical module, 2 ... Board | substrate, 3 ... Optical element, 4 ... Optical fiber, 5 ... Optical path conversion member, 6 ... Fixed part, 7 ... Optical fiber for optical path conversion, 8 ... First holding member, 9 ... Second holding 10: Bending part, 11, 12 ... Linear part, 13 ... Bending and bending part, 14 ... Front end face, 15 ... Rear end face, 16 ... Upper face, 17 ... Lower face, 18 ... Front face, 19 ... Rear face, 20 ... Left side face 21 ... right side surface, 22 ... circular arc part, 23 ... guide projection, 24 ... upper surface, 25 ... lower surface, 26 ... front side, 27 ... rear side, 28 ... left side surface, 29 ... right side surface, 30 ... concave part, 31 ... guide groove 32 ... concave top surface, 33 ... concave front surface, 34 ... concave left side, 35 ... concave right side surface, 36: space, 37, 38 ... groove, 39 ... end face, 40 ... tip, 41 ... flat plate, 42 ... back Edge

Claims (3)

An optical path converting optical fiber, and a first holding member and a second holding member assembled so as to sandwich the optical path converting optical fiber, the optical path converting optical fiber being disposed at a predetermined position, and the first holding member When assembling the second holding member, in the optical path conversion member in which the optical path conversion optical fiber is bent along with the assembly,
The optical path conversion optical fiber extends toward the incident end and the output end continuously from a bent portion formed by bending the optical path converting optical fiber accompanying the assembly, and one end and the other end of the bent portion, respectively. Provided with an incident side linear part and an output side linear part,
The first holding member connects the incident side plane portion and the emission side plane portion, which are arranged orthogonally to each other, and connects the incident side plane portion and the emission side plane portion to bend the optical path converting optical fiber accompanying the assembly. And the arc portion is disposed on the inner edge side of the bent portion,
The second holding member is disposed near and perpendicular to the incident side plane part and the emission side plane part, and in the vicinity of the intersection of the incident side plane part and the emission side plane part and on the outer edge side of the bending part. A space portion to be arranged, and the space portion is formed in a shape in which the space expands in a direction away from the outer edge of the bent portion,
An incident-side groove that accommodates the incident-side linear portion is provided at a position corresponding to the incident-side planar portion of the first holding member in the incident-side planar portion of the second holding member, and the emission side of the second holding member In the position corresponding to the emission side plane part of the first holding member in the plane part, an emission side groove part that accommodates the emission side linear part is provided ,
The incident-side groove extends from an edge of the incident-side flat surface portion to an intermediate portion of the incident-side flat surface portion, and an edge of the incident-side groove portion on the space portion side and one of the optical fibers for optical path conversion. And the exit-side groove extends from an edge of the exit-side flat portion to an intermediate portion of the exit-side flat portion, and an edge of the end of the exit-side groove on the space portion side. A part of the optical fiber for optical path conversion is in contact,
The edge of the incident side groove on the side of the space and the edge of the end of the exit side on the side of the space are aligned with each other when the bent part moves toward the space. An optical path changing member arranged and formed at a position where contact is possible . In the optical path changing member according to claim 1,
The optical path converting optical fiber has a bending bending portion formed by bending the bending portion in a direction away from the arc portion after the first holding member and the second holding member are assembled.
The optical path conversion member , wherein the space portion is formed in a shape in which the space exists on an outer edge side of the bending deflection portion . 3. The optical path conversion according to claim 1, wherein the optical element is surface-mounted on a substrate, the optical fiber extends in a direction intersecting the optical axis of the optical element, and the optical path is disposed between the optical element and the optical fiber. optical module characterized by comprising a member.

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